[Feature]: Invoke-AzOperationalInsightsQuery should have -NoCache switch that adds

### Description of the new feature

KQL searches are cached by default. In the log analytics tool in Azure Portal, no-cache is explicitly requested by the browser. When trying to do a polling KQL search, Invoke-AzOperaitonalInsightsQuery can be behind for a while until the cached result expires.

### Proposed implementation details (optional)

Add a switch that adds the nocache header to the KQL request.

Start with the Invoke-AzOperationalInsightsQuery entry point and trace where its KQL request headers are built. Add the -NoCache switch so the request includes the no-cache header, then verify that polling queries no longer use cached results.

Written by the indexing model from the issue text.